using System;
using System.Collections.Generic;
using System.Linq;
class Program
{
static string InputPattern = "InputX";
static List<string> GetInputList()
{
var WillReturn = new List<string>();
if (InputPattern == "Input1") {
WillReturn.Add("100 4");
WillReturn.Add("30 40 120");
WillReturn.Add("30 40 30");
WillReturn.Add("30 40 1500");
WillReturn.Add("30 40 40");
//1660
}
else if (InputPattern == "Input2") {
WillReturn.Add("100 4");
WillReturn.Add("13 15 31415");
WillReturn.Add("12 13 92653");
WillReturn.Add("29 33 58979");
WillReturn.Add("95 98 32384");
//-1
}
else if (InputPattern == "Input3") {
WillReturn.Add("5000 5");
WillReturn.Add("1000 1000 1000000000");
WillReturn.Add("1000 1000 1000000000");
WillReturn.Add("1000 1000 1000000000");
WillReturn.Add("1000 1000 1000000000");
WillReturn.Add("1000 1000 1000000000");
//5000000000
}
else if (InputPattern == "Input4") {
WillReturn.Add("10000 20");
WillReturn.Add("4539 6002 485976");
WillReturn.Add("1819 5162 457795");
WillReturn.Add("1854 2246 487643");
WillReturn.Add("1023 4733 393530");
WillReturn.Add("1052 6274 289577");
WillReturn.Add("1874 2436 167747");
WillReturn.Add("1457 4248 452660");
WillReturn.Add("2103 4189 174955");
WillReturn.Add("3057 5061 319316");
WillReturn.Add("4898 4953 394627");
WillReturn.Add("1313 2880 154687");
WillReturn.Add("1274 1364 259598");
WillReturn.Add("3866 5844 233027");
WillReturn.Add("1163 5036 386223");
WillReturn.Add("1234 4630 155972");
WillReturn.Add("2845 4978 442858");
WillReturn.Add("3168 5368 171601");
WillReturn.Add("3708 4407 394899");
WillReturn.Add("3924 4122 428313");
WillReturn.Add("2112 4169 441976");
//2727026
}
else {
string wkStr;
while ((wkStr = Console.ReadLine()) != null) WillReturn.Add(wkStr);
}
return WillReturn;
}
struct LRWInfoDef
{
internal long L;
internal long R;
internal long W;
}
static List<LRWInfoDef> mLRWInfoList = new List<LRWInfoDef>();
static void Main()
{
List<string> InputList = GetInputList();
long[] wkArr = { };
Action<string> SplitAct = pStr =>
wkArr = pStr.Split(' ').Select(pX => long.Parse(pX)).ToArray();
SplitAct(InputList[0]);
long W = wkArr[0];
foreach (string EachStr in InputList.Skip(1)) {
SplitAct(EachStr);
LRWInfoDef WillAdd;
WillAdd.L = wkArr[0];
WillAdd.R = wkArr[1];
WillAdd.W = wkArr[2];
mLRWInfoList.Add(WillAdd);
}
// 価値合計の最大値[重さ合計]なセグ木
var InsSegmentTree = new SegmentTree(W + 1);
InsSegmentTree.Update(0, 0);
foreach (LRWInfoDef EachLRWInfo in mLRWInfoList) {
for (long I = W; 0 <= I; I--) {
long FromRangeSta = I - EachLRWInfo.R;
long FromRangeEnd = I - EachLRWInfo.L;
// 範囲外の場合
if (FromRangeEnd < 0) break;
FromRangeSta = Math.Max(FromRangeSta, 0);
FromRangeEnd = Math.Max(FromRangeEnd, 0);
long MaxVal = InsSegmentTree.Query(FromRangeSta, FromRangeEnd, 0);
if (MaxVal < 0) continue;
long CurrVal = InsSegmentTree.Query(I, I, 0);
long NewVal = MaxVal + EachLRWInfo.W;
if (CurrVal < NewVal) {
InsSegmentTree.Update(I, NewVal);
}
}
}
long AnswerVal = InsSegmentTree.Query(W, W, 0);
if (AnswerVal < 0) {
Console.WriteLine(-1);
}
else {
Console.WriteLine(AnswerVal);
}
}
}
#region SegmentTree
// SegmentTreeクラス (RMaxQ and 1点更新)
internal class SegmentTree
{
private long[] mTreeNodeArr;
private long UB; // 木のノードの配列のUB
private long mLeafCnt; // 葉ノードの数
// ノードの添字を引数とし、範囲の開始添字と終了添字を持つ配列
private struct RangeInfoDef
{
internal long StaInd;
internal long EndInd;
}
private RangeInfoDef[] mRangeInfo;
// コンストラクタ
internal SegmentTree(long pLeafCnt)
{
// 簡単のため、葉ノード数を2のべき乗に
long ArrLength = 0;
for (long I = 1; I < long.MaxValue; I *= 2) {
ArrLength += I;
mLeafCnt = I;
if (pLeafCnt < mLeafCnt) break;
}
// すべての値をlong.MinValueに
UB = ArrLength - 1;
mTreeNodeArr = new long[UB + 1];
for (long I = 0; I <= UB; I++) {
mTreeNodeArr[I] = long.MinValue;
}
// ノードの添字を引数とし、範囲の開始添字と終了添字を持つ配列の作成
mRangeInfo = new RangeInfoDef[UB + 1];
for (long I = 0; I <= UB; I++) {
if (I == 0) {
RangeInfoDef WillSet1;
WillSet1.StaInd = 0;
WillSet1.EndInd = mLeafCnt - 1;
mRangeInfo[I] = WillSet1;
continue;
}
long ParentNode = DeriveParentNode(I);
RangeInfoDef ParentRangeInfo = mRangeInfo[ParentNode];
RangeInfoDef WillSet2;
long Mid = (ParentRangeInfo.StaInd + ParentRangeInfo.EndInd) / 2;
if (I % 2 == 1) { // 奇数ノードの場合
WillSet2.StaInd = ParentRangeInfo.StaInd;
WillSet2.EndInd = Mid;
}
else { // 偶数ノードの場合
WillSet2.StaInd = Mid + 1;
WillSet2.EndInd = ParentRangeInfo.EndInd;
}
mRangeInfo[I] = WillSet2;
}
}
// 親ノードの添字を取得
private long DeriveParentNode(long pTarget)
{
return (pTarget - 1) / 2;
}
// 子ノードの添字(小さいほう)を取得
private long DeriveChildNode(long pTarget)
{
return pTarget * 2 + 1;
}
// 葉ノードの配列の添字を木の添字に変換して返す
private long DeriveTreeNode(long pLeafArrInd)
{
long BaseInd = UB - mLeafCnt + 1;
return BaseInd + pLeafArrInd;
}
// 葉ノードの配列のK番目の値をNewValに変更
internal void Update(long pK, long pNewVal)
{
long CurrNode = DeriveTreeNode(pK);
mTreeNodeArr[CurrNode] = pNewVal;
// 登りながら更新
while (CurrNode > 0) {
CurrNode = DeriveParentNode(CurrNode);
long ChildNode1 = DeriveChildNode(CurrNode);
long ChildNode2 = ChildNode1 + 1;
mTreeNodeArr[CurrNode] =
Math.Max(mTreeNodeArr[ChildNode1], mTreeNodeArr[ChildNode2]);
}
}
// 開始添字と終了添字とカレントノードを引数として、最大値を返す
internal long Query(long pSearchStaInd, long pSearchEndInd, long pCurrNode)
{
long CurrNodeStaInd = mRangeInfo[pCurrNode].StaInd;
long CurrNodeEndInd = mRangeInfo[pCurrNode].EndInd;
// OverLapしてなければ、long.MinValue
if (CurrNodeEndInd < pSearchStaInd || pSearchEndInd < CurrNodeStaInd)
return long.MinValue;
// 完全に含んでいれば、このノードの値
if (pSearchStaInd <= CurrNodeStaInd && CurrNodeEndInd <= pSearchEndInd)
return mTreeNodeArr[pCurrNode];
// そうでなければ、2つの子の最大値
long ChildNode1 = DeriveChildNode(pCurrNode);
long ChildNode2 = ChildNode1 + 1;
long ChildVal1 = Query(pSearchStaInd, pSearchEndInd, ChildNode1);
long ChildVal2 = Query(pSearchStaInd, pSearchEndInd, ChildNode2);
return Math.Max(ChildVal1, ChildVal2);
}
}
#endregion